here are suggestions for you, since you say you are not computer savy.

the computer are you are building is a little expensive for the parts you getting and you don't have a warrenty or tech support. for the money you can get:

a. dell
http://configure.us.dell.com/dellsto...tudioxps-435mt
it has a warrenty, the new i7 processor and an ati 3450 video card. this system is ok....just upgrade the ram to 6gb for $150 and buy the ati 4850 from best buy for $175 and you will have a nice machine for under $1300

or
2. ibuypower
http://www.ibuypower.com/ibp/store/c...r.aspx?mid=349
i7 processor and the ati260. configure the case and power anyway you want, but i would upgrade the memory to 6gb and do it yourself, they are a little expensive. plus you get a free copy of far cry 2.

or
c. cyberpower
http://www.cyberpowerpc.com/system/G...reme_XT/detail
i7 processor and the ati 4870 which is better than the 260. free liquid cooling and for $20 less you can upgrade the 1tb HDD to a 1TB raid0. (much faster setup and needed with the i7)

all of these are cheaper and much faster than what you are planning to build yourself, plus they come with a warrenty and tech support.